Hi, I've never heard about this and I don't think it exists in Geneva! Besides normal single trip tickets and 1 week/month/year pass, there is a ticket for 20 hours starting at 9 am till 5 am (7chf) or a ticket  for the whole day 24h (10chf).

There are also pre-paid cards you can get to the value 20chf, 30chf or 50chf - this may be more what you are after? They can be bought at tpg offices and most newsagents.

They don't give you discounts on tickets but they have a couple of advantages over paying by coins. When you have 200chf of used cards you can take them back to a tpg office and exchange them for a free 20chf card. Also, if you only have a small amount left on it - say 10cents - you can still buy a single ticket (value 3chf)!

It used to be that if you bought a 30chf card you'd get 3chf free on it and 5chf free on a 50chf card - last time I bought one, though, there wasn't any free credit on it.